Piston



Nov. 11, 1930.

J. TATTERU AL PISTON I Filed Nov. so, 1925 45 Fig. 1 is w Fig.

Patented Nov.l 11,. 1930 UNITED. STATES JOHN rarrna AND WILLIAM E.

ywvrsNr OFFICE,

Paseos. or cnrcaoo, rnnrmi's mamma mea november so, 1925. serial in. 72,360.

'- 5 employed more or less in internal combustion en ines to overcome the faults which ten to obtain when the pistons are formed entirely of either cast iron or aluminum, the term aluminum being used in this instance to include alloys comprising a, relatively large proportion of that metal. A piston formed entirely of cast iron is relatively heavy and the inertia thereof during the operation of the en ine decreases the etil- .15 ciency of the eniitele guminum pistons are.

relatively light reater co-eilicient of-- thermal expansion of aluminum makes it necessary to allow excessive clearance between the piston and the c linder wall, which clearance detractsfrom t e efficiency of the en ne. v ur invention has among its other objects, the production of an improved composite piston which is -convenient, durable and satis-l 26 factory for use wherever found applicable.

Another object of the invention isto pro: vide a composite piston which may be manufactured at a relatively low cost.l

Still another object of the invention is to 30 provide a relatively light piston which does not requiremuch clearance between it and its cylinder wall. Y

Many other objects and advantages of the construction herein shown and described will I' 35 be obvious to those skilled in the art from the disclosure herein given.

To this end our invention consists in the novel construction, arrangement and combination of parts herein shown and described,

i 40 and more particularly pointed- 'out in the claims.

In the drawing, wherein like reference characters indicate like or corresponding parts:

a central section through' a piston embodying our invention;

Fig. 2 is a section taken on the line 2-2 of l Fig.v 1; 1g. 3 1% a. section taken on the lme 3-3 of Fig. 4 is a fragmentary section through a piston embodying another forrnof the invention. Ll

In Figs. 1, 2 and 3 of the drawing, we have shown a piston embodying one form of the invention.l and adapted to be used in an internal combustion engine or the like. The improved piston preferably comprises a body portion 10 formed from aluminum,

but it is to be understood'that we are limited` v60v to the use of aluminum only to theextent in` dicated in the appended claims.

Embedded in the body portion 10`is alleli-- cal member 11 formed of cast iron. The member 11 preferably comprises a plurality 65 of spaced turns 12, which, in this' instance, are substantiall rectangular in cross section. Formed in the elical member 11 are undercut grooves 14 into which the metal of the body portion 10 projects.

The improved plston is preferably formed (I by casting the body portion 10 in a. suitable mold, or the e uivalent, the helical member 11 being suitab y positioned in the mold before the aluminum is poured therein. Obviously, the fused aluminum will flow into the f grooves 14 and' prevent subsequent displacementlgf the turns 12 relative to thebody portion In one embodiment ofthe invention, the 130 l 'outerA diameter of the helical member 11 is substantially equal to that of the body portion 10, but less clearance is allowed between the piston and the cylinder wall (not shown) than is customary in the manufacture of aluminum pistons. f

During the operation of an internal combustion engine, which includes our improved pistons, the helical member 11 of each piston tends to prevent the normal increase or decrease of diameter of the body portion 10 as the temperature within the engine rises, it

being understood'that the coeicient of thermal expansion of aluminum is greater than that of cast iron vand that aluminum e lands with a lgmreater rapidity than cast iron. ow ever, t e helical member 11 does not materially retard longitudinal expansion or contraction of the body member functions as a spring. y

portion 10 as the helical loo "The bodyportion may be provided with annular grooves 16 adaptedto accommodate piston rings (not shown). A

the customary gs 18 may be cast integral with plurality of lu the body portion 10to hold a plurality of threaded studs 19, whereby bearing blocks 20 may be secured within the body portion. As shown, each bearing block 20 is provided with a plurality of drilled holes 22 adapted to accommodate thestuds 19 and is held firmly seated on thelugs 18 by nuts 24, or the equivalent, vscrew-threaded upon the studs 19. A wrist pin 25 may be mounted in the i bearing blocks 20 to providemeans whereby the piston may be operatively connected to a piston rod, which is indicated at 26. If `de- A sired, the wrist pin 25 may be provided with a renewable sleeve 27. n y

y In Fig. 4, we have illustrated another form ofthe invention embodied in-,a piston comprising a body portion 10 members 11 embedded therein, turns of each 'of the members being disposed between turns of the other member. It will be noted that the outer diameter of the body portion 10l is less than that of the helical members 11, which, in practice, may be made of diameters allowing substantially the same clearance that is allowed in the manufacture of cast by Letters Patent is:

1. A piston having a helical member of at least one complete turn embedded therein and secured thereto by tongue and groove construction. Y

2. A piston comprising a cylindrical body portion and a plurality of Ahelical members embedded/in said body portion so snugly as to form substantially a unitary part thereof, turns of each of said members being disposed between turns of the other member.

y 3. A wall, and

said wall, the inner and outer surfaces of said insert forming a part of the corresponding surfaces of said cylindrical wall.

4. A piston comprising a cast cylindrical wall, and a cast helical insert embedded in tion and forming a part of the inner an with two helical arrangement and combination ofv piston comprising a cast cylindrical a cast helical insert embedded in wall having spaced helical turns,`and a helical insert disposed b tween said turns.y

6. A plston comprising a cast cylindrical wall, and a cast insert arranged in a helical slot extending through the wall.

7. A' piston comprising a cast cylindrical Wall, and a plurality of cast helical inserts embedded in said wall, to form ortions of the outer surface thereof, turns o each of said inserts being disposed between turns of the other insert.

8. A piston comprising a body ortion, and a helical insert embedded in said bod pord, outer surfaces thereo 9. A piston comprising a body ortion, and a helical insert embedded in said body portion, said insert being substantially H-shaped in cross section, and the legs of said ing part `of the inner' and outer surfaces of said body portion. 10. A piston comprising a cast cylindrical wall and a cast helical insert embedded in said wall, said insertk bein substantially H-shaped in cross section andgthe legs of said H forming faces of sai wall, said insert comprising a plurality of turns.

art of the inner and outer sur- H form- V In testimony whereof,we have hereunto signed our names.

` JOHN TATTER.

WILLIAM H. PASCOE.

said wall and 'forming portions of the inner and outersurfaces thereof, said insert com-V prising aplurality of turns.

5. A pasten comprising a cast 'cylindrical l i 1li CERTIFICATE OF CORRECTION.

ment Ne. 1,781,031. Granted November 11, 1930, te

JOHN TAT'TER ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, line 67, claim 5, for the word "disposed" read cast; and that the said Letters Patent should be read with this correction that the same may conformto the record of the case in the PatentvOffice.

Signed and sealed this 20th day of January, A. D. 1931.

l M. J. Moore, (Seal) Acting Commissioner of Patents. 

